Thanks for the reply Andy – yeah I tried removing the pose morph tag as well, problem remains.
I think I’ve literaly just found the issue, and came back to report it. I forgot that the original teeth have some very slight animation to them ( so slight I forgot about it ) and when the volume builders were built, the null that the source teeth were in was NOT zeroed out at the time, which has led to this problem.
A classic example of becoming overwhelmed by a scene and forgetting the very early steps of setting it up! Im now having to rebuild it and see if the resolution Im suggesting above actually solves it. Will come back and update if so.
Thanks again.